Method for imaging intracavitary blood flow patterns

Abstract

Heart diseases are detected by producing a series of ultrasound images that depict the blood flow pattern in the left ventricle at successive phases of the cardiac cycle. The blood flow pattern images are produced by injecting a diluted contrast agent and tracking the contrast agent particles as they flow through the left ventricle by acquiring ultrasound images at a high frame rate.

1. A method for in vivo imaging of flow pattern of blood in a ventricle of a heart of a subject, the method comprising:
 a) administering particles configured to mix with blood flowing in the ventricle of the heart of the subject to produce a differentiatable acoustic signature; 
 b) acquiring, using ultrasonic energy reflected back to a transducer array of an ultrasound imaging system located externally from the subject, images of the ventricle of the heart at a substantially high frame rate selected to track the particles flowing in the ventricle of the heart in successive ones of the ultrasound image frames; and 
 c) producing images of the ventricle of the heart indicating at least one of delays of redirected outflow from the ventricle of the heart and delays closing a valve of the heart associated with the ventricle based on the tracking of the particles. 
 
     
     
       2. The method as recited in  claim 1  wherein the ventricle of the heart includes a left ventricle of the subject. 
     
     
       3. The method of  claim 1  wherein the substantially high frame rate is at least 200 frames per second. 
     
     
       4. The method of  claim 1  wherein step a) includes injecting a contrast agent. 
     
     
       5. The method of  claim 4  wherein step a) includes diluting an ultrasound contrast agent. 
     
     
       6. The method of  claim 5  wherein the ultrasound contrast agent is diluted to administer one of 10 micrograms/kg of body weight of the subject and 1 mL dissolved in 100 mL/min of saline at a rate of approximately 0.01 to 0.05 mL/min. 
     
     
       7. The method of  claim 4  wherein the contrast agent includes a perfluoropropane gas-filled, lipid-stabilized microbubble contrast agent. 
     
     
       8. The method of  claim 1  wherein step b) includes acquiring physiological data from the subject temporally correlated with the acquired images. 
     
     
       9. The method of  claim 8  wherein the physiological data includes ECG data. 
     
     
       10. The method of  claim 1  further comprising step d) overlaying data indicators over the produced images indicating at least one of kinetic energy, momentum, pressure gradient, velocity, acceleration, direction, vorticity, turbulence, and laminarity. 
     
     
       11. The method of  claim 1  further comprising step d) diagnosing one of acute ischemia, heart failure, mitral valve regurgitation, and dyssynchrony from the images of the ventricle of the heart indicating the flow characteristics therein based on the tracking of the particles. 
     
     
       12. A method for diagnosing heart disease, the method comprising:
 a) acquiring a series of ultrasound images using an ultrasound transducer array located externally from the subject of a left ventricle of a heart at a substantially high frame rate during a succession of cardiac phases of a cardiac cycle; 
 b) producing a series of flow pattern images from the acquired ultrasound images depicting the flow of particles in blood flowing in the left ventricle at successive cardiac phases and indicating at least one of delays of at least one of flow from the left ventricle and valve operation associated with the left ventricle; and 
 c) examining the series of flow pattern images during each cardiac phase to detect flow characteristics indicative of a disease. 
 
     
     
       13. The method of  claim 12  wherein step a) includes administering a contrast agent and acquiring the series of ultrasound images after a delay of a number of cardiac cycles. 
     
     
       14. The method of  claim 13  wherein the contrast agent is a perfluoropropane gas-filled, lipid-stabilized microbubble contrast agent and is diluted to administer one of 10 micrograms/kg of body weight of a subject being imaged and 1 mL dissolved in 100 mL/min of saline at a rate of approximately 0.01 to 0.05 mL/min. 
     
     
       15. The method of  claim 12  wherein the substantially high frame rate is at least 200 frames per second. 
     
     
       16. The method of  claim 12  further comprising step d) indicating a presence of a disease based on the examining in step c). 
     
     
       17. The method of  claim 16  wherein the disease includes at least one of acute ischemia, heart failure, mitral valve regurgitation, and dyssynchrony from the series of flow pattern images. 
     
     
       18. The method of  claim 12  further comprising step d) acquiring physiological data from a subject being imaged temporally correlated with the series of flow pattern images produced in step b). 
     
     
       19. The method of  claim 18  wherein the physiological data includes ECG data. 
     
     
       20. The method of  claim 12  further comprising step d) overlaying data indicators over the series of flow pattern images indicating at least one of kinetic energy, momentum, pressure gradient, velocity, acceleration, direction, vorticity, circulation, turbulence, and laminarity.